A spice rack lives in the worst spot in the kitchen: next to the stove, under the steam, one splash from the sink. The material you pick decides whether it still looks right in a year or films over and stains by spring. Here's the real comparison, not the product-photo version.
Stainless steel: heavy, clean, unfazed
The stainless rack wipes clean after an oil splatter and won't warp near heat the way thin plastic does. It's also heavier, so it stays where you put it instead of skating across the counter when you brush past. Near a sink or stove — which is where spice racks live — that resistance to stain and slide is the whole point.
Bamboo: warm look, needs a dry spot
Bamboo looks calmer than steel and suits a wood-toned kitchen. But it's organic, so it wants to stay dry — a rack right under the kettle or beside the dish drain will eventually spot if you don't wipe it. Fine on a dry counter; risky in the steam lane. Think of it as the pretty one that needs a little care.
Plastic: cheap, and it shows
Plastic is the lowest cost and the lowest ceiling. A full row of glass jars bows thin walls, and once bowed it never straightens. Near heat it can warp; near sauce it films and stains in a way steel shrugs off. For a light, dry, low-traffic shelf it's acceptable — for the working counter it's the one you replace.
The material question is really "how hard does this counter work?" If it's the daily cooking spot, steel earns the difference; if it's a calm dry nook, bamboo is lovely. Match it to the splash, not the photo. See the bamboo side argued in our bamboo vs plastic organizer piece.